First conditional
If + present, will + base (review).
The first conditional describes a real or very likely situation in the future: something that will happen IF a certain condition is met. The structure has two clauses. The if-clause (the condition) uses the present simple tense — never 'will'. The main clause (the result) uses 'will' or 'won't' followed by the base form of the verb. Either clause can come first; when the if-clause is first, a comma separates the two clauses. 'Unless' means 'if … not', so it introduces a negative condition without using 'not' a second time: 'Unless you hurry, you will miss the bus' = 'If you don't hurry, you will miss the bus'. 'When' is used instead of 'if' when the event is certain or expected rather than conditional: 'When I get home, I will call you' (getting home is certain). To avoid confusion: 'if' = possible/uncertain future; 'when' = certain/inevitable future. For example: 'If you study hard every evening this week, you will pass the exam on Friday — but unless you revise the grammar rules, you won't feel confident.'
Rules
- 1Use the present simple (not 'will') in the if-clause: 'If it rains, …' — never 'If it will rain, …'.
- 2Use 'will / won't + base verb' in the main (result) clause: '… we will stay at home.'
- 3Either clause may come first; put a comma after the if-clause only when it leads the sentence.
- 4'Unless' = 'if … not': 'Unless you leave now' = 'If you don't leave now'; do not add another 'not'.
- 5Use 'when' (not 'if') for certain or expected future events: 'When the lesson ends, we will go home.'
Practice
10 easy · 10 medium · 10 hard